I hadn't realised it comes in a 4" throat version. And 300mm long, too. That's great.
Are they available anywhere?
The RCF MR8N301 8" midrange speaker may be yet another option. They are roughly the same thing, and can be bought new from usspeaker or parts express.
With the horn (RCF H6000), it covered 500Hz-3kHz. That horn doesn't seem to be available any more, but maybe that's cos it wasn't very good - it looks fairly basic and was very small (16.18" W x 13.7" H x 3.27" D), so a slightly larger DIY version would probably be an improvement.
Do you mean you can get it flat 250Hz-2kHz at 106dB without any boost (only subtractive eq)?
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Remember that we are talking about the Seos 24-4 which actually is a 30" horn, not the ordinary "little" Seos 24.
These horns are great! We had a group buy on 5 pairs here in Norway for about two years ago, I have not seen anyone else using them yet. Probably because no one knows what to use them for, the horns were designed by one of us 5 that bought them together and Auto-Tech can now produce them for anyone.
The 2169H driver + phase plug and gaskets can be bought from any JBL service parts dealer. Personally I bought everything from prosysav.com and got a nice package price.
Yes, this horn/driver compo play 250-2k (down to 220Hz in my room because of room gain) with 106db sensitivity @ 1w/1m without boost, just a few substractive PEQ's as all constant directivity horns need. Put 200 watts in and we are talking about 130db+! With other drivers you will be far away from this thought, the CMCD driver is almost a compression driver. 8" cone driver with phase plug to remove empty space in front of the driver and a 4" exit + closed rear camber, you won't get performance near this with a 5,25" driver without phase plug bolted directly to the horn and without any closed rear chamber...
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I was thinking similar things. Intercontinental postage is another reason to use what one has:
- customs and shipping means I've paid $800 for drivers that sold for $500.
I ordered some 5" drivers last year, partly to see how they'd go in a similar project ...and I'm still waiting to get them.
Some of POOH's examples with small drivers (and no phase plug or rear chamber) look great. I've had less extended but still useful results from cheap drivers. Even a defective driver gave me 103dB
The RCF MR8N301 is an 8" and goes to nearly 3kHz with their very basic looking phase plug (an egg on sticks) - cloning or improving that seems within reach of a decent DIY effort.
Phase Plugs
"One of the simplest phase plug implementations involves increasing the baffle cutout diameter and suspending a conical shaped wooden (or other solid material) plug in the centre [...] I utilised this type of plug in my twin 8" design, and it allowed operation of an 8" speaker up to a crossover point of 2.5kHz"
Attachments
With a 4th order electronic high pass on a horn that load well to 300 Hz (like in the examples I posted) 125 db output would not be unreasonable with the Faital 5" or B&C 6" drivers. Either driver will have sensitivity over 104 db with 2.83 volts. Both can handle 80 watts or more and without the horn are 99 db sensitive. Just do the math. Neither driver has a problem with output when loaded in a horn.
http://www.faitalpro.com/en/products/LF_Loudspeakers/product_details/index.php?id=101010100
http://www.bcspeakers.com/products/lf-driver/6-5/8/6pev13
http://www.faitalpro.com/en/products/LF_Loudspeakers/product_details/index.php?id=101010100
http://www.bcspeakers.com/products/lf-driver/6-5/8/6pev13
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I wasn't disagreeing with you.
"~115dB peaks from 10 watts" and "sensitivity over 104 db with 2.83 volts" is the same cake, sliced different ways
I wasn't disagreeing with you.
"~115dB peaks from 10 watts" and "sensitivity over 104 db with 2.83 volts" is the same cake, sliced different ways
I know, my point is the Faital 5"driver LewinskiH01 has in his possession should he choose to use in any good horn should be considered competent compared to any other cone driver and is no way limited in output for the most demanding home audio geek.
seos ?
Will they ship to the United States ?
How can I find the cost ?
I might even organize a group purchase to reduce the shipping costs average per pair.
Thanks !
Will they ship to the United States ?
How can I find the cost ?
I might even organize a group purchase to reduce the shipping costs average per pair.
Thanks !
I've been in touch with Lukasz at Autotech.pl and he's not coming through as the most helpful. And I haven't even started talking about logistics, which usually are cumbersome in my case. So not sure if this will happen, but looking into it. I asked for detailed drawing of the throat/driver base so to better understand how to assemble.
BTW, I am in no way discarding the CMCD. Just looking at starting off with the M5N12 because I have it and Pooh has shown it has similar behavior to the CMCD within my intended range. It can't go as low given the size difference, and based on my trials with DIY I might not be able to reach 2000Hz xo as I wish. But if I can try the 24-4 with these and see the shortcomings where I know the M5N12 shortcomings are...then next step would be getting CMCD.
I agree sensitivity will be high enough. Not a concern.
I did look into making basic phase plugs and while I could do it, I'm starting without them to reduce complexity. Of course I could never get to the CMCD levels, but starting with a 5" and extending it to a 2000Hz xo doesn't seem so difficult. And I could be very happy with a 400Hz xo instead of 250Hz since I'm 4-ways anyways.
Jorg's experience with Seos 24-4 + CMCD and supporting the path is of great assurance. Seems like a good path.
This horn is wider than allowed by the wife, though, so that's another can of worms
. Thinking of a JBL DD67000 kind of setup, although in my case TPL atop, Seos, and twin 10" below. And separate subwoofers. Still wide and maybe too low
Nevertheless I'm encouraged by how this is turning out. Thank you all for the great food for thought!
BTW, I am in no way discarding the CMCD. Just looking at starting off with the M5N12 because I have it and Pooh has shown it has similar behavior to the CMCD within my intended range. It can't go as low given the size difference, and based on my trials with DIY I might not be able to reach 2000Hz xo as I wish. But if I can try the 24-4 with these and see the shortcomings where I know the M5N12 shortcomings are...then next step would be getting CMCD.
I agree sensitivity will be high enough. Not a concern.
I did look into making basic phase plugs and while I could do it, I'm starting without them to reduce complexity. Of course I could never get to the CMCD levels, but starting with a 5" and extending it to a 2000Hz xo doesn't seem so difficult. And I could be very happy with a 400Hz xo instead of 250Hz since I'm 4-ways anyways.
Jorg's experience with Seos 24-4 + CMCD and supporting the path is of great assurance. Seems like a good path.
This horn is wider than allowed by the wife, though, so that's another can of worms
. Thinking of a JBL DD67000 kind of setup, although in my case TPL atop, Seos, and twin 10" below. And separate subwoofers. Still wide and maybe too low Nevertheless I'm encouraged by how this is turning out. Thank you all for the great food for thought!
Latest from Lukasz at Autotech.pl: Seos 24-4 cost 500 Euro (pair), plus 500 to 600 Euro shipping to the US and customs clearance. Too rich for my blood
So, back to the drawing board.
Given this thread started as a question about horns with compression drivers and ended in CMCD/cones with horns, I am now thinking cone driven again:
1) Rectangular conical, double expansion. This is my current prototype.
2) The horn JBL uses the CMCD with. Need to look for the model and references.
3) Make a Seos 24-4
Regarding #3, maybe I could 3D print and initial rough mold? Need to find a 3D printer large enough...and figure out the mathematical expression of the shape. It's elliptical oblate spheroid, right?
Latest from Lukasz at Autotech.pl: Seos 24-4 cost 500 Euro (pair), plus 500 to 600 Euro shipping to the US and customs clearance. Too rich for my blood
So, back to the drawing board.
Given this thread started as a question about horns with compression drivers and ended in CMCD/cones with horns, I am now thinking cone driven again:
1) Rectangular conical, double expansion. This is my current prototype.
2) The horn JBL uses the CMCD with. Need to look for the model and references.
3) Make a Seos 24-4
Regarding #3, maybe I could 3D print and initial rough mold? Need to find a 3D printer large enough...and figure out the mathematical expression of the shape. It's elliptical oblate spheroid, right?
Well, you are now at the stage where I have been, several years ago. Once you agreed that going "modular" was a wise choice, it opened up all kinds of future possibilities. YOUR MID-BASS section. That is where the pulse, the heart-n-soul, the driving factor of your speaker systems' sonic signature will arise from. Since you already have twin drivers, yet in separate enclosures, you might consider allowing the upper most of the two vertical stacked units to run up to a higher frequency (700-800Hz). If I recall correctly, we also decided the mid bass section is where we decided to address the baffle step, so this tactic should align with that, as well. Your dsp should dictate the crossover point, and a passive, speaker level crossover should be used for the low-pass, baffle step section.
For upper mid range, to be considered, this:
Faital Pro LTH142- Faital Pro LTH142 1.4" long elliptical tractrix horn. Faital Pro LTH142 elliptical tractrix horns available here at US Speaker.
p.s. I'll address the mid-bass at another time, as it would be off topic to this thread.
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If you can't get a big print (or not at a reasonable price), there are many techniques you could use.
a) Like this: pretty example
(I've done a small variant of this: it is a lot of work / mess / waste)
b) Like this: same one I linked earlier - a construction pic is further in that thread
(less work, but still a lot. It would have gone faster with lighter materials)
c) Like this:
Azurahorn -Le Cleac'h Acoustic Horns - DIY Manafacture
(I haven't done this, but I really like his idea of using "polyurethane foam – built up in layers from sheet"
If I was going to build (from scratch) something like the SEOS 24-4 at home, I think I'd use a technique that borrowed from all of the above:
(1) use Hornresp to calculate your horn shape, and generate an output file in 28mm increments
(2) buy some sheets of 3mm MDF & and 25mm polystyrene foam
(3) glue them together to get 28mm layers
(4) proceed like in example a), but using this much lighter material that you can quickly cut and smooth by hand.
Check with DIY Sound Group about Seos 24-4, them seem to be the US dealer for Auto Tech? They probably buy several horns at the same time to reduce shipping costs.Latest from Lukasz at Autotech.pl: Seos 24-4 cost 500 Euro (pair), plus 500 to 600 Euro shipping to the US and customs clearance. Too rich for my blood
So, back to the drawing board.
Given this thread started as a question about horns with compression drivers and ended in CMCD/cones with horns, I am now thinking cone driven again:
1) Rectangular conical, double expansion. This is my current prototype.
2) The horn JBL uses the CMCD with. Need to look for the model and references.
3) Make a Seos 24-4
Regarding #3, maybe I could 3D print and initial rough mold? Need to find a 3D printer large enough...and figure out the mathematical expression of the shape. It's elliptical oblate spheroid, right?
You can also get a JBL horn for CMCD, for example the K64MH. Just look up JBL spec sheets on speakers by Googling CMCD/2169H and then find the tech manual on these speakers to get JBL part numbers. Then it's just to send an inquiry to a JBL dealer to get availibility and prices. I know JBL have made several different horns for the CMCD and I am sure some of them still are available.
Yeap. I thought so too. Unfortunately they don't carry the 24-4.
Reading the CMCD Technical Note, they state Progressive Transition Waveguides are the ideal match for CMCD. Looking into the PT Waveguides Technical Note they focus on high frequency and note a couple of midrange + high freq integrated units like the K64MH you noted. I guess I would buy one and cut off the high frequency horn...I can't find a complete list of PT Waveguides to see if there is a midrange unit only.
FWIW, this speaker https://www.jblpro.com/ProductAttachments/7200_64.pdf is essentially a K64MH with a CMCD and the directivity is rather underwhelming for a constant directivity horn, isn't it? And considering the conversation we had above, they seem to be small for my target passband.
Comparing the above directivity graph with the one for the JBL 3730 Screen Array system here https://www.jblpro.com/ProductAttachments/3730_SS_Approved_091412_web.pdf
We can see directivity from 500 to 2000Hz is a lot better for the 3730 (range covered by its midrange unit) than the directivity of the K64MH.
The midrange horn in the 3730 is part #445024-001. Anybody happen to know what kind of horn this is? Might it be a PT Waveguide? It's used with a 195H which is 6.5" cone though...
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